Mule deer may seem ubiquitous in the Roaring Fork Valley, but Colorado Parks and Wildlife say numbers of the species are below its target in some key areas near Rifle. The state agency plans to kill mountain lions and bears in an effort to help grow the deer population.
The so-called “predator control study” would last three years, beginning next spring. CPW has contracted with a federal agency called Wildlife Services, which will trap and kill between five and 10 mountain lions and 10 to 20 bears annually on the Roan Plateau outside of Rifle.
CPW wildlife biologist Chuck Anderson said the goal is to drop the number of young fawns killed by bears and mountain lions. The predator study comes after years of studying habitat fragmentation caused by oil and gas development in the area, which is no longer seen as a limiting factor.
“Basically, there’s nothing showing us that there’s any evidence of habitat limitations in this population. And the forage conditions are good,” Anderson said. “We’ve been doing some habitat improvement projects in the area and the vegetation has responded well.”
The deer population is still below the goal set by CPW, and Anderson said mountain lions and black bears could be to blame. This may come as a surprise to those used to seeing bruins focused on acorns, berries and trash.
“Actually bears are very efficient predators of young ungulates, both elk and deer, and actually the highest mortality rates I have in deer on the Piceance are from black bears,” Anderson said. “So far we’re averaging about 14 percent of the fawns that we collar each year are taken by black bears.”
So, why is CPW concerned with a prey species being eaten by its natural predators? Anderson explained that it’s as much about recreational hunting as ecology.
“Mule deer are somewhat the iconic species of the west,” Anderson said. “They’re a very valued game species; obviously, there’s a strong economic incentive for having healthy deer populations.”
Critics of this type of study said that motivation is exactly the problem, and that by killing predators to increase their prey, CPW would disrupt a complex system and fragile social structure.
Wendy Keefover is a native carnivore protection manager at The Humane Society. She said the study is unnecessary and removing established adult mountain lions may have many unintended consequences. Younger males may become more aggressive to assert dominance.
“You may potentially increase predation initially of mule deer, and even create more conflicts between humans and livestock,” Keefover said.
Anderson, with CPW, said it’s difficult to track numbers of predators like bears and mountain lions, so the agency can’t say what percentage of those animals will be killed. He anticipates that the populations will rebound quickly in what he called a small-scale study dealing with unique circumstances.
“This is not a large scale thing,” Anderson said. “In fact, it’s been pretty well demonstrated that large-scale predator reduction efforts are not very successful.”
Although CPW said this is a focused study that targets lions and bears in a relatively small area, Keefover is concerned about how those animal populations will recover.
“Both those animals have a really hard time in the human dominated landscape surviving to adulthood and then reproducing themselves successfully,” Keefover said.
If the proposed study gets final approval from the state, the killing of bears and lions will happen in the spring, when there is no hunting season for those species. Wildlife Services, an arm of the U.S. Department of Agriculture, will capture the predators using cage traps, hounds and potentially even foot snares, and shoot the animals. David Moreno, wildlife biologist for the agency, said the meat will be donated and the hides become state property.
The next informational meeting is scheduled for Sept. 19 in Denver.
